Effects of CO2-driven ocean acidification on the early developmental stages of invertebrates

Abstract

CO 2 emissions arising from the burning of fossil fuels have altered seawater chemistry far more rapidly than the Earth has previously experienced, and the rate and extent of this change are expected to affect shallow water marine organisms. The increased CO 2 diffuses from the atmosphere into ocean surface waters, resulting in increased partial pressure of CO 2 , and reduced [CO 32 -] and pH. The CO 2 -driven ocean acidification leads to a decrease in calcium carbonate (CaCO 3 ) saturation state in the ocean surface waters and has potential impacts on calcifiers. The present study focuses on the effects of ocean acidification on early developmental and reproductive stages of calcifiers, both of which are believed to be the most vulnerable stages to environmental change within a life cycle. Laboratory experiments revealed that ocean acidification has negative impacts on the fertilization, cleavage, larva, settlement and reproductive stages of several marine calcifiers, including echinoderm, bivalve, coral and crustacean species. There appear to be significant ontogenetic impacts and species-specific differences in tolerance to the high CO 2 levels. The conclusion is that future changes in ocean acidity will potentially impact the population size and dynamics, as well as the community structure of calcifiers, and will therefore have negative impacts on marine ecosystems. Further studies are needed to evaluate the potential impacts on non-calcifiers, as well as the synergistic impacts of ocean acidification and climate change. Studies should also focus on the adaptive capability of marine organisms, which will be crucial to the ability to forecast how marine organisms and ecosystems will respond to the world's oceans as they warm and acidify.

Effects of ocean acidification on immune responses of the Pacific oyster Crassostrea gigas

“…Over the past 10 years, accumulating evidence suggests that OA could result in delayed embryonic development [8,9], decreased larval growth [10,11] and increased mortality [12] of many marine mollusks. Moreover, OA stress has also been found to affect many physiological processes, such as calcification [13], energy metabolism [14] and behavior [15,16] of calcifying organisms.…”

Ocean acidification and temperature rise: effects on calcification during early development of the cuttlefish Sepia officinalis

“…Kurihara 2008;Dupont and Thorndyke 2009). Even though this view is discussed controversly Byrne 2011), projected changes in seawater abiotic conditions could have strong effects on the development of embryos, larvae and juveniles and their calcification capacities.…”

“…In organisms possessing complex life-cycles, it is often assumed that early-life stages may be the most vulnerable to environmental perturbations, including high pCO 2 (Pörtner and Farell 2004;Pörtner 2008;Kurihara 2008), especially in invertebrates (e.g. Kurihara 2008;Dupont and Thorndyke 2009).…”

Sea urchin fertilization in a warm, acidified and high pCO2 ocean across a range of sperm densities

“…Ocean acidification has dire consequences for larvae due to impaired larval calcification and hypercapnia (Clark et al, 2009;Dupont et al, 2008;Kurihara, 2008). However, in areas of strong warming such as southeast Australia, embryos of species like H. erythrogramma that are sensitive to thermal effects (Byrne, 2009;Byrne et al, 2009) may not reach the larval stage in a warm ocean regardless of pH.…”

“…Hypercapnia and acidification exert negative effects on the metabolism, biochemistry and skeleton formation of marine species (Pörtner et al, 2005;Pörtner 2008;Widdicombe and Spicer, 2008). Tolerance to climate change and other anthropogenic stressors varies greatly among species making it difficult to make broad extrapolations on how marine communities will respond to climate change (Dupont and Thorndyke, 2009;Kurihara, 2008;Pörtner, 2008;Przeslawski et al, 2008).…”